Repetition. The secret to Taekwondo proficiency is repetition. Repetition develops trained reflexes, control, and accuracy. To paraphrase President Coolidge, nothing takes the place of practice and persistence in practice. Repetition is used extensively in class but you should stress that students use it extensively in their personal training. Students shown new techniques in class, they learn to perform the techniques by repetitious training at home.
Repetition may become boring during class. Repetition drills may be made more challenging by frequently changing the parameters, such as changing the stance or changing the speed of execution. You may incorporate a drill into games or contests, such a last to finish must do extra repetitions or must designate the next technique for a drill.